Bradley Wiggins goes into Saturday's penultimate stage of the Tour de Romandie with the yellow jersey on his back but just a second's lead on his nearest rival.

The British champion, who took control of the race through Francophone Switzerland with a remarkable sprint victory on Wednesday, finished safely in the main bunch but had his lead slashed by stage three's winner, Luis León Sánchez. The Spaniard finished on the same time as Wiggins but a 10-second stage-winner's bonus has thrown open a six-day race that looked comfortably within Team Sky's grasp.

The Londoner looked tired on the run-in to Charney after initially looking well-placed for a second stage victory in three days, perhaps an accidental victim of the punishing pace his team set at the head of the peloton.

Wiggins's Australian team-mate, Michael Rogers is third, level on time with Sánchez, who is riding for Rabobank.

Sánchez now poses a significant threat to Wiggins's hopes of securing a second stage-race win of the season, and will need to be closely guarded over the three climbs towards Sion in Saturday's stage. Wiggins may expect to win Sunday's last-day 16.5km time trial but Sánchez is a three-times Spanish champion in that discipline.

Mark Cavendish, working during this race with Wiggins for the first time, will lead Team Sky in the Giro d'Italia, which starts in Denmark next Saturday. The World Road Race champion has had a nine-man team specifically tailored to his aim of winning the Maglia Rosso Passione sprinters' prize, with his long-time domestique Bernhard Eisel expected to organise a lead-out train also containing the Britons Geraint Thomas, Ian Stannard, Peter Kennaugh and Ben Swift.

While the Spaniard Juan Antonio Flécha may target individual stage wins, only the young Colombians Rigoberto Urán and Sergio Henao can expect to target a high placing on general classification.

"The Giro is one of my favourite races of the season and we've got a good squad to go and win stages," said Cavendish. "Geraint, Pete and Swifty have just come off the track so they should have that explosive power which will be important in the first week, and the rest of the team have all done well in the classics.

"We want to win the [opening stage's] time-trial as well and hopefully that will get us the [race leader's] pink jersey."